Interest in the preparation and use of water-soluble polymers has increased dramatically in recent years because of regulations relating to pollution abatement. Various synthetic and natural water-soluble polymers exhibit superior activity in waste water clarification, flocculation, sludge dewatering, paper retention and drainage, and in petroleum recovery operations. These high molecular weight water-soluble polymers are available in three forms, namely, as solids, as dilute aqueous solutions, and as water-in-oil emulsions. High molecular weight solid water-soluble polymers are usually difficult to dissolve despite the high solubility in water. When added to water, the solid particles swell and the exterior portions of the particles become covered with a gelatinous water-polymer mixture which retards the movement of water into the particle. As a result, excessive times are required to achieve complete solubility, or else substantial loss in effectiveness in an application area will result from the incompletely dissolved polymer. To alleviate this problem, recent improvements in the art have involved the development of more rapidly dissolving water-in-oil emulsions of polyelectrolytes. However, these materials are difficult to handle, and tend to separate in the form of a polymer-poor oil phase and a polymer-rich phase. They contain hydrocarbon oils which are flammable, foul application equipment and result in cloudy solutions of slow-dissolving polymer when added to water.
Accordingly it is an object of the present invention to provide a liquid polymer composition which comprises a high molecular weight water-soluble vinyl addition polymer, water, one or more surfactants, and a water-soluble polyalkylene glycol, or water-soluble ethoxylated alcohol, alkylphenol, or fatty acid.
It is a further object to provide a method for preparing high solids dispersions of high molecular weight water-soluble polymers in a water-soluble medium.
It is a further object to provide a composition which is composed of a stable, easily handled liquid water-soluble polymer dispersion in a water-soluble medium which is non-flammable, non-toxic, which is storage-stable, and which furnishes a rapidly dissolving polymer when added to water, resulting in clear solutions.
In brief, the foregoing objects and advantages are attained by use of the new compositions of matter produced by forming a water-soluble vinyl addition polymer as a water-in-oil suspension or emulsion in an inert hydrophobic organic liquid containing at least one surfactant and subsequently
a. separating the aqueous polymer phase from the oil phase and mixing the said aqueous polymer phase with water, at least one surfactant, and a water-soluble organic carrier, or PA1 b. mixing the water-in-oil suspension or emulsion with at least one surfactant and a water-soluble organic carrier and removing the inert hydrophobic organic liquid by distillation. PA1 R.sup.4 is alkylene containing 1 to 4 carbon atoms; R.sup.5 is lower alkyl containing 1 to 4 carbon atoms; Z is an anion, and with the proviso that unit B is present only in combination with unit A and in minor amounts.
The nature of the invention will become more apparent to those skilled in the art by the preferred embodiments and description of the invention which follows.